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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds genuine non-schema context: a hard cap of 10 results per call and the fact that each result carries the official organizer page for registration plus a BJJ Square list page — useful for deciding whether this call is sufficient or a follow-up is needed.

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 the purpose, then the source provenance, then the filter and return shape. The parenthetical list of federation names is slightly expendable, but every sentence still carries information an agent would otherwise have to guess.

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 no output schema, the description correctly takes on the burden of explaining returns (max 10 per call, each with organizer page and calendar page) and the filter dimensions. What it omits — pagination or how to get beyond the 10-result cap beyond a vague pointer to the calendar page — is minor but real.

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% and every parameter (from, to, country, lang, limit) is documented inline with patterns, defaults and bounds. The description only restates 'search by country and date range' and adds no syntax or format detail beyond the schema, so the 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 and resource ('Upcoming BJJ and grappling competitions') and immediately scopes the data source as an aggregated public calendar with named feed providers. It is trivially distinguishable from find_gyms/get_gym/list_places, which cover different entities.

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 clear operating context: 'Search by country and date range,' which maps to the primary filters. It does not name a when-not condition or an alternative tool, but the sibling set (gyms, places) does not overlap with competitions, so no routing ambiguity is left open.

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