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

Annotations already cover safety (readOnly, idempotent, non-open-world), and the description adds substantial context on top: no-auth usage, 25-per-page sizing, best-match ordering, count as total, and the match/match_note markers for fuzzy results. The untrusted_seller_text warning is a genuine security disclosure absent from the schema and annotations.

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?

Front-loaded with purpose, then pagination, then matching semantics, then a security note — a sensible ordering. The semicolon-chained sentences are dense and the matching clause is a long run-on, costing a little readability, but no sentence is 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 7-parameter, zero-required search tool with an output schema, the description covers pagination, result ordering, result counts, fuzzy-match flags, and untrusted text handling. An agent has everything needed to call and interpret it correctly.

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. The description does add real meaning about matching behavior (accents ignored, plurals, synonyms, spelling slips) and the cursor pairing rule, which goes beyond the schema's per-parameter text, but it stops short of elaborating on most individual parameters.

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?

Opens with a specific verb and resource: 'Search second-hand items people sell on Agent Market', then extends scope to digital goods and API credit packs. The scope is precise enough to distinguish it from siblings like market_find_skills or market_get_listing, which are skill-directory and single-listing lookups rather than marketplace search.

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?

Gives actionable operational rules: empty arguments list everything, no sign-in required, and when next_cursor is non-null send it back as cursor with identical arguments. It does not, however, explicitly say when to prefer this over siblings such as market_get_listing for a known item, so there is no exclusion guidance.

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