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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered; the description adds return-shape context that no output schema provides — every exercise carries a video and the identifier field is named edb_exercise_id. It does not mention pagination behavior or ordering, which the per_page/page params imply but never explain.

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, both dense and front-loaded: what the tool returns first, then the ID hand-off to consumers. Nothing is repeated from the schema or annotations.

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 an eight-param read tool with no output schema, the description gives the entity shape, all filter facets, and the ID's downstream use. Missing only pagination/total-count behavior, which matters given page and per_page exist but is a modest gap.

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 75% and the description covers the remaining gap by enumerating all six filter dimensions (name, body part, target muscle, equipment, type, difficulty), making the purpose of each clear even where the schema just says "From list_library_*." It also clarifies that the returned id is edb_exercise_id. Pagination params are left entirely to the schema.

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 the verb (list/browse) implicitly and the resource precisely: exercises from the app library, each with a video, filterable by six named dimensions. The sibling list contains near-neighbors like search_exercises, list_exercise_templates, list_my_exercise_videos and list_favorite_exercises, but the description never distinguishes this tool from them, so it stops short of a 5.

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?

The second sentence gives a concrete downstream use: the returned id is the edb_exercise_id accepted by create_workout and add_exercise_to_program_day, which tells an agent exactly when to reach for this tool. It offers no exclusions, though — nothing says when to prefer search_exercises or list_exercise_templates instead.

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