Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Without annotations, the description discloses a key behavioral trait: 'Re-encrypts every item with a fresh derived key and new salt', indicating a heavy mutation operation.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two short sentences, no filler, front-loaded with the core action. Every word adds value.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given no annotations and no output schema, the description covers purpose, prerequisite, and side effect reasonably well, though missing error handling details.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 0%, and while the description maps old_pin to 'current PIN' and new_pin to 'new PIN', it adds no further semantic details like format or constraints.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a clear verb-resource phrase 'Rotate the PIN' and adds context about re-encrypting items, making it distinct from siblings like lock or unlock.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

States 'Requires the current PIN', which is a prerequisite, but does not provide explicit when-to-use or when-not-to-use guidance relative to sibling tools.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description discloses that the tool decrypts and returns a value and errors on missing keys. However, it does not address other behavioral aspects like idempotency, side effects, or rate limits. The transparency is adequate but not thorough.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single sentence with no filler, directly stating the core function and error behavior. It is well-structured and front-loaded.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description covers the basic operation and error case, but omits the return value type (e.g., string, number). Given no output schema, this leaves ambiguity. For a simple tool, it is mostly complete.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The description says 'for a given key', matching the schema, but adds minimal meaning. It mentions the error condition for missing keys but does not explain key format or constraints. With 0% schema description coverage, the description provides only marginal additional context.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool decrypts and returns the value for a given key, and errors if the key does not exist. This distinctively separates it from siblings like store (create/update) and list (enumerate).

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance is provided on when to use this tool versus its siblings. The description does not mention alternatives or prerequisites, leaving the agent to infer usage from the name alone.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Discloses that the PIN is never stored, only a PBKDF2 hash for verification. Mentions default path and env variable. With no annotations, this description does a good job at behavioral transparency, though it could note whether it creates directories.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three sentences, each adding essential information: action/failure condition, security detail, path configuration. No filler words, front-loaded with the core purpose.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple initialization tool with no output schema and one parameter, the description covers the purpose, failure condition, security aspect, and configuration. It could mention what happens if the missing directory must be created, but overall it's sufficient.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% with the pin parameter described as 'PIN at least 4 characters.' Description echoes that requirement ('PIN at least 4 characters') but does not add additional semantics beyond the schema. Baseline score applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Clearly states the action (initialize), the object (vault file), and the means (with a PIN). Distinguishes from siblings like fetch, list, etc., by focusing on first-time setup. Explicitly mentions failure condition if vault exists.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Implicitly tells when to use: when no vault exists. Explicitly says 'Fails if a vault already exists,' which is a clear exclusion condition. Also provides default path and env override. Lacks explicit sibling comparison but context makes it clear.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries full burden. It discloses that values stay encrypted on disk, reassuring the tool is non-mutating and safe. However, it does not elaborate on other behavioral aspects like idempotency or latency, which are minor for a list operation.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two concise sentences, each adding distinct value: listing keys and encryption behavior. No wasted words, front-loaded with the core action. Exemplary conciseness for a simple tool.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given zero parameters and no output schema, the description covers the tool's essential function. It could be improved by specifying the output format (e.g., returns a list of key names), but for a simple list operation the current description is nearly complete.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema has no parameters and schema description coverage is 100%, so the description adds no parameter details, which is appropriate. The lack of parameters is inherent and does not require further explanation.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool lists all keys in the vault, specifying the exact resource (keys) and scope (all). It distinguishes from sibling tools like 'fetch' (retrieve a value) and 'store' (add a key), making purpose unambiguous.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage for listing keys but provides no explicit guidance on when to use this tool vs. alternatives like 'fetch' or 'store'. No conditions or exclusions are mentioned, leaving the agent to infer from context.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Discloses that the derived key is cleared and that subsequent operations need unlock. No annotations provided, so description carries full burden; it adequately covers the behavioral impact.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, no wasted words. First sentence front-loads the primary action; second adds important context.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Fully sufficient for a parameterless tool with no output schema. Covers action, consequence, and recommended usage pattern.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

No parameters, so baseline score of 4 applies. Description does not mention parameters (none exist), so no deduction.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Clearly states 'Clear the derived key from memory' with a specific verb and resource. Distinguishes from siblings by explaining that after this, store/fetch/list/remove require unlock again.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Provides explicit guidance: 'Recommended at the end of a session.' Implies context but no explicit exclusions or alternatives; siblings exist but not directly compared.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Without annotations, the description must convey critical behavioral traits. It explicitly states 'permanently delete,' indicating irreversibility. However, it does not describe any side effects, required permissions, or what happens to related data, leaving gaps for a destructive operation.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single sentence with no wasted words. However, it is so brief that it sacrifices completeness; a slightly longer description front-loading essential details would be more effective without sacrificing conciseness.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple tool with one parameter and no output schema, the description is complete in terms of purpose, but for a destructive operation without annotations, more behavioral context is expected. The description lacks details on what the deletion entails, making it incomplete for safe use.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The description mentions 'item' as the target, weakly linking to the 'key' parameter. With 0% schema description coverage, the description should explain the meaning of 'key' (e.g., what format, where to obtain it), but it adds only minimal context. The agent cannot determine how to specify the item beyond guessing it's a string identifier.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states 'permanently delete an item from the vault,' which is a clear verb+resource combination. It distinguishes from siblings like fetch (retrieval) and store (insertion), leaving no ambiguity about its purpose.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance on when to use this tool versus alternatives. The description does not mention prerequisites, contexts where deletion is appropriate, or cases where it should be avoided. The agent is left to infer usage from the tool's name and siblings.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations provided, so description carries full burden. It explicitly lists all reported properties: existence, unlock status, path, item count. No behavioral surprises.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Single sentence that is front-loaded with the verb and immediately lists outputs. Every word adds value; no redundancy.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given zero parameters, no output schema, and a straightforward status tool, the description is fully adequate. An agent can correctly select and understand the tool's output.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

No parameters exist. With zero parameters, the baseline is 4. The description adds value by explaining what the tool returns, compensating for lack of output schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool reports on vault file existence, unlock status, path, and item count. It uses a specific verb 'report' and resource 'vault file'. It distinguishes from siblings like lock/unlock which are action-oriented.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies when to use the tool (to check vault status) but does not explicitly contrast with alternatives. However, the context of sibling tools (action verbs) makes the usage clear.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description discloses key behaviors: encryption algorithm (AES-256-GCM), random IV generation per encryption, and overwriting existing values. This provides good transparency, though it could mention side effects like potential performance impact.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, tightly worded sentence that efficiently conveys the core action, encryption details, and overwrite behavior with no superfluous words.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

While the description covers encryption and overwriting, it lacks information about the return value (e.g., success indicator or ciphertext), potential error conditions, or prerequisites like initialization. For a tool with no output schema, this is a notable gap.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% with descriptions 'Item name.' and 'Plaintext value to encrypt.' The tool description adds encryption context (AES-256-GCM) but does not elaborate further on parameter formats or constraints beyond the schema. Baseline of 3 is appropriate given high schema coverage.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states it encrypts a value with AES-256-GCM and saves it under a given key, clearly indicating a write operation. This distinguishes it from siblings like fetch (read) and remove (delete).

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage for storing encrypted values and mentions overwrite behavior, but lacks explicit guidance on when to use vs. alternatives like lock or init. No exclusions or prerequisites are given.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Discloses key derivation details (PBKDF2, iterations, cipher) and error behavior on wrong PIN. No annotations exist, so description carries full burden. Could mention if multiple unlock calls are allowed.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three efficient sentences, front-loaded with purpose, then algorithm and consequences. No extraneous information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Missing prerequisite information (e.g., whether 'init' must be called first). With siblings like init, this is a notable gap. Otherwise covers effect and lifecycle well.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema has 0% description coverage, but description explains that pin is used with salt to derive the key and that wrong pin returns an error. Adds significant meaning beyond the raw schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Clearly states the tool unlocks the vault for a session, distinguishes from siblings like lock and init. Specifies the algorithm used and the effect on other tool availability.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Provides context on when to use (before other operations) and lifecycle (until lock or process exit). However, does not explicitly state when not to use or mention alternatives like init.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.