search_fonts

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

Beyond the readOnlyHint annotation, the description discloses non-obvious behavior: fuzzy query matching order (exact, prefix, substring, all words), AND-combined filters, compact rows, id-bearing output, and browse-without-query semantics. This gives an agent a realistic model of how the tool behaves before invoking it.

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 earning its place. The description is front-loaded with the core purpose, then gives query semantics, filter behavior, output note, and the no-query browsing alternative. There is no redundancy or filler.

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 tool with 10 optional parameters and no output schema, the description is fairly complete: it explains query behavior, filtering, output purpose, and browsing mode. A small gap is that it does not describe the shape of the returned rows beyond 'compact' and carrying the id, and offset is left undocumented in the schema as 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 description coverage is high (80%), so the baseline is 3. The description adds meaningful semantics beyond the schema by explaining how the query parameter is matched and that filters combine with AND logic. It does not explain the offset or category parameters further, but the schema already documents most parameters clearly.

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 a specific verb and resource: 'Search the Fontsource catalog of 2000+ open-source fonts.' It clearly differentiates this discovery tool from the sibling get/download/index tools by mentioning that its rows 'carry the id every other tool needs,' positioning it as the lookup step in the workflow.

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 gives clear usage context: it is the tool to find fonts and their ids, which are then needed by other tools. It also explains a distinct browsing mode: 'Filters without a query browse a category.' However, it does not explicitly name when not to use it or directly contrast it with get_font or index_fonts by name.

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