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

Annotations already declare readOnlyHint and openWorldHint=false, but the description adds genuinely new behavior: a plan-gated restriction on multi-filter queries and signed media links in results. It stops short of describing pagination behavior, error behavior when a plan cap is hit, or how limit interacts with plan caps.

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 dense sentences, front-loaded with the resource and corpus size, then constraints, then return shape. With no output schema present, the sentence describing returned fields earns its place rather than duplicating structured data.

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 15-parameter tool with no output schema, the description covers purpose, plan constraint, and a return-value summary, which is most of what an agent needs. Gaps remain around pagination via offset/limit and what happens when a plan cap is exceeded.

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 67%, and the description compensates by stating cross-cutting filter semantics the schema does not: filters are optional, matching is case-insensitive, and combining filters is plan-gated. It adds no per-parameter detail for the undocumented enums (force, category, mechanic, difficulty) or for offset/includeMedia, so it is not fully complete.

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+resource and a concrete corpus size ("Search 1,900+ exercises"), which clearly separates it from single-record siblings like get_exercise and get_exercise_media. It does not explicitly distinguish itself from find_similar_exercises or find_exercise_alternatives, so it falls short of full sibling differentiation.

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?

States that filters are optional and that combining two or more requires the Starter plan, which is real usage guidance an agent must know before composing a query. However, it never says when to prefer this over list_exercise_filters or find_similar_exercises, leaving alternative selection to inference.

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