Todo MCP

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

Annotations already indicate the tool is not read-only and not destructive. The description adds no further behavioral detail, such as what happens if the todo is already completed or if there are side effects.

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?

A single sentence that is perfectly concise and front-loaded with the essential action, containing 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?

For a simple tool with one parameter, no output schema, and clear sibling tools, the description is complete enough. It clearly states the purpose and required input.

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% and the only parameter 'id' is documented in the schema. The description adds no additional meaning or context beyond the 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 specific action 'mark as completed' on a specific resource 'existing todo', distinguishing it from sibling tools create_todo and get_todos.

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 completing a todo but does not explicitly state when to use it versus alternatives, nor does it mention prerequisites or conditions (e.g., todo must exist, idempotency).

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?

The annotations indicate this is not read-only (readOnlyHint=false) and not destructive (destructiveHint=false), so the agent knows it's a mutation but not a destructive one. The description merely restates the mutation behavior, adding no extra context such as whether validation occurs, what side effects (like notifications or indexing) might happen, or if the title must be unique.

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 very concise at one sentence, which is appropriate for a simple tool. There is no wasted text. However, it is perhaps too minimal for the utility it provides, missing opportunities to add usage nuance without becoming verbose.

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 the tool has 2 parameters, no output schema, and no nested objects, the complexity is low. However, the description is still incomplete: it does not mention what the tool returns (e.g., the created todo object or an ID), whether errors occur for duplicate titles, or if any constraints beyond the schema apply. This leaves the agent guessing about the response and edge cases.

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 description coverage is 100%: both 'title' and 'description' have descriptions in the schema. The tool description does not add any information beyond what is in the schema, but due to high coverage, a baseline of 3 is appropriate. No additional context is provided, but the schema already explains the parameters sufficiently.

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 says 'Create a new todo item.' This is clear enough about the verb ('create') and resource ('todo item'), but it doesn't distinguish this tool from its siblings ('complete_todo' and 'get_todos'). The name itself is also quite generic, and the description adds no additional specificity.

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?

There is no guidance on when to use this tool versus alternatives. For example, it doesn't mention that 'create_todo' is for adding new items while 'complete_todo' is for marking items done, or that 'get_todos' is for listing. An agent would have to infer this from the tool names 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?

Annotations already declare readOnlyHint=true and destructiveHint=false, so the tool's safety profile is clear. The description adds value by disclosing the optional filtering behavior for completed todos, which is not conveyed by annotations alone.

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?

A single, front-loaded sentence that efficiently communicates the core purpose and key option. No extraneous words; every part earns its place.

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 optional parameter and no output schema, the description covers the essential behavior. However, it does not specify the return structure (e.g., an array of todo objects), which could help an agent anticipate response format.

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 description coverage is 100% for the single parameter, including its default and description. The tool description essentially paraphrases the parameter (optionally including completed todos), adding no further semantic guidance beyond the 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 verb ('Get') and resource ('all todo items'), distinguishing it from the sibling tools which are write operations (complete_todo, create_todo). The optional inclusion of completed todos further clarifies scope.

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 retrieving todos, but does not explicitly state when to exclude completed items versus when to include them. No guidance on alternatives or when not to use this tool is provided.

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