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

Annotations already cover the read-only, idempotent, non-destructive, non-open-world profile, and the description adds genuinely new context: it is a free curated map, and it enumerates the returned fields (name, address, phone, website, page link). The instruction to pass the link to the user is a behavioral directive the annotations cannot convey.

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?

Purpose and scope are front-loaded in the opening clause and the coverage countries follow immediately; the return fields and link instruction close it usefully. The middle sentence is a long run-on stacking search modes, but no sentence is redundant.

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 8 optional params and no output schema, the description carries the return-value explanation itself and does so concretely. It omits result-volume expectations and no-match behavior, which would matter for an agent deciding between a broad and narrow query.

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 lat/lon, city, kind, limit, query, radius_km and instrument are all already documented, including enum meanings. The description only restates the three search modes and the instrument/kind filters, adding no format or precedence rules beyond the schema — 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?

States a specific verb ('Find') and enumerates the exact resources: drum schools, teachers, cajon classes, studios, circles and shops, on a named service. It also fixes the geographic scope (Russia, Kazakhstan, Armenia, Belarus and other countries), which no sibling tool (cajon_catalog, find_songs, free_drum_tools) covers.

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 explicit entry modes — by city, by coordinates with a radius, or by part of name/address — plus filtering by instrument and kind, which tells the agent how to construct a call. It lacks any exclusion or fallback guidance (e.g. what to do when a city returns nothing), and never names siblings as alternatives.

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