Circuit

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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=false), so the bar is lower. The description still adds real context beyond structured data: it is 'Free', and it enumerates what each result contains (id, price in USDG, summary, 30-day usage). It does not mention rate limits or auth needs, so not a 5.

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 short sentences: purpose and query examples first, then return fields, then cost. Every sentence carries distinct information and nothing is redundant with the schema.

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?

With no output schema, the description usefully names the return fields, and annotations cover the safety profile. Missing only minor operational detail such as pagination or result ordering, which keeps it just under 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?

Schema description coverage is 100%, so limit, query, category and maxPrice are already fully documented with defaults, ranges and examples. The description adds no syntax or format detail beyond the schema, which is the expected baseline of 3.

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?

Specific verb ('Search') plus a precisely scoped resource ('Circuit's paid AI agent skills by capability') with three concrete example queries. It implicitly separates itself from get_skill by framing results as a list of summaries, but never names or contrasts a sibling explicitly, which keeps it short of a 5.

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 example queries ('phishing link', 'token price', 'summarize a web page') effectively show the intended usage pattern, and the schema notes that an empty query lists everything. However, there is no guidance on when to prefer this over get_skill or try_skill, and no exclusions, so usage is only implied.

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 cover safety (readOnlyHint=true, openWorldHint=false), so the description only needs incremental context. It delivers that with 'Free' and by enumerating what metadata comes back, including pricing and payment instructions, which matters for deciding whether a skill is usable. It omits error behavior for an unknown skill_id.

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 compact sentence that leads with the resource and scope, then the payload, then the cost note. No filler and nothing buried.

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?

With no output schema, the description carries the burden of describing returns and does so thoroughly by naming every field type returned. For a simple one-parameter read tool with safety annotations, nothing material is missing.

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 schema already explains skill_id including its format and origin ('bastion/url-risk' from find_skills). The description adds nothing about the parameter, so the baseline 3 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?

Specific verb+resource scoped to 'one skill', immediately contrasting with the plural find_skills sibling. The list of returned details (input/output schema, example, price, usage, uptime, rating, payment) makes the tool's identity unmistakable.

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 phrase 'one skill' implies this is the drill-down after a search, but the description never names find_skills, try_skill, or list_recipes as alternatives or states the condition for choosing this tool. Usage is inferable rather than stated.

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 cover the safety profile (readOnlyHint=true, openWorldHint=false), so the description's main added value is the cost note ('with the cost of one run. Free.'). That is genuinely useful behavioral context — it signals the pricing model — but the phrase 'cost of one run' is ambiguous and the description says nothing about what the listing contains or how it is returned.

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 efficient sentence with no filler, and the cost caveat is placed at the end where it reads as a bonus. The parenthetical examples ('vet a token, install a dependency safely, screen untrusted input') are helpful concretization rather than padding.

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 zero-parameter list tool with no output schema, the description is adequate but incomplete: it explains what a recipe is and its cost, yet never confirms that output is a list of recipes nor what identifying fields (name, description) an agent would receive to act on them.

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 tool takes zero parameters with 100% schema coverage, so there is nothing for the description to disambiguate. Baseline 4 applies with no compensating work needed.

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 defines the resource ('workflows that chain several skills') but never states the actual verb of the tool — that it lists/returns recipes. The action is only inferable from the name 'list_recipes', and no sibling such as find_skills or get_skill is named to differentiate 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?

There is no when-to-use guidance and no reference to alternatives. An agent cannot tell from the text whether list_recipes should be chosen over find_skills or get_skill, or under what conditions browsing recipes beats searching skills.

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 cover the safety profile (readOnlyHint, openWorldHint), and the description adds concrete behavioral context the annotations do not: a per-day quota (3 free calls), an input size cap (500 characters), and the existence of an unlimited paid tier. It still omits what a call returns or what happens when the quota is exhausted.

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 tight sentences with no filler; the primary action is front-loaded and the constraint (size, quota) follows immediately.

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?

There is no output schema, so an agent might want return-value detail, but for a skill-proxy tool the description plus the nested input schema and annotations give enough to invoke it correctly. Quota-exhaustion behavior is the only notable omission.

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%, so the baseline is 3, but the description adds a substantive constraint not present in the schema — the 500-character cap on the nested 'input' object — plus the note that input must match the skill's own 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?

States a specific verb and resource ('Run a skill once for free') with a clear scoping constraint on input size. It clearly differs from the discovery siblings (find_skills, get_skill, list_recipes), though it never explicitly names an alternative for paid/full invocation.

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 free-tier framing (3 calls/day, 500-char input, 'paid calls have no such limits') implies when to use it — quick trials rather than production runs — but there is no explicit when-to-use statement or named alternative for unlimited execution.

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