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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety is covered. The description adds real context beyond them: the exact alive_in_year interval rule including the 80-year fallback when the death year is unknown, and the fact that image_url is an absolute URL that can be null. It says nothing about result ordering or relevance scoring, which keeps it from 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?

Two sentences, front-loaded with the core action and filters, then the return shape. Every clause carries information (filter semantics, fallback rule, nullable image URL) with no 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 six-parameter search with no output schema, the description covers the action, the filterable dimensions, the tricky filter's exact semantics, and enumerates the returned fields including the nullable one. An agent has everything needed to call it and interpret the response.

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, and the description genuinely earns above that by explaining alive_in_year as 'born <= year <= died, or born + 80 years when the death year is unknown' — a semantic the schema does not contain. The city/country/query/limit parameters are only restated at the level the schema already provides.

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 ('Full-text search of artists') plus the searchable fields (name, biography) and the narrowing filters, which is far beyond a restatement of the name. It stops short of naming a sibling such as get_detail_artist for single-record lookup, so the boundary with siblings is left implicit.

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?

Usage is implied by 'full-text search' versus the get_detail_* siblings, and the optional filters suggest a discovery workflow. However, there is no explicit statement of when to prefer this over get_detail_artist or search_fts, and no exclusions or prerequisites are given.

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