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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety and open-world profile is covered structurally. The description adds no behavioral context beyond that – no pagination, ranking, or result-shape caveats – and mostly restates what the schema's parameter descriptions already say (query, default limit 10).

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, front-loaded with the core purpose and ending with the useful sibling pointer. No filler, though the middle sentence duplicates schema content and could have been dropped.

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 two-parameter read-only search with an output schema and full schema coverage, the description supplies purpose, parameter restatement, and sibling routing. Nothing essential is missing, though it does not describe result ordering or any edge-case behavior.

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 both parameters are already documented. The description repeats the schema text verbatim ('q: Shop search keyword', 'limit: Max shops to return (default 10)') without adding format, syntax, or filtering nuance, so 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?

The description uses a specific verb+resource ('Returns Etsy shops matching a keyword') and explicitly distinguishes itself from the listings sibling by pointing to etsy_search. An agent can pick this over etsy_shop or etsy_search without opening any schema.

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?

It gives a clear routing rule ('Use etsy_search to search Etsy listings'), which tells the agent when NOT to use this tool for listings. It does not, however, address when to prefer this over etsy_shop (shop detail lookup) or mention any prerequisites, so the guidance is directional but incomplete.

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