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

Annotations already establish read-only, idempotent, non-destructive, closed-world behavior, so the bar is lower; the description still adds real context by defining search semantics (describe what the project does), the both-shelves default, and the ordering of results. It omits anything on pagination beyond the limit parameter or on what happens with zero matches.

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?

Four tight sentences, front-loaded with purpose and then defaults and narrowing options; nothing is padding. Minor overlap with the schema's enum text is the only waste.

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 correctly takes on the return contract — "short summaries, best matches first" — and covers defaults, narrowing, and query style. An agent has everything needed to form a correct call.

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 each parameter already carries a description, so the baseline is 3. The description adds the most value for `query` — signaling that natural-language descriptions of function work better than project names — but its treatment of `shelf` and `useWithoutCoding` largely restates the enum descriptions already in 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?

States a specific verb and resource — "Find open-source AI projects by what they do" — and immediately clarifies that the query is semantic/functional rather than name-based, with two concrete examples. This clearly separates it from get_project (fetch one) and list_categories (enumerate slugs) without needing the schemas.

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?

Explicitly explains the default behavior ("Searches both shelves unless 'shelf' is given") and the two optional narrowing axes (category, useWithoutCoding). It does not say when to prefer this over a sibling such as get_project for retrieving full details, so it stops short of full alternative routing.

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