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

Annotations already declare readOnlyHint=true, openWorldHint=false, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context beyond annotations: it specifies what is returned (summary, cues, safety, progressions), notes that display depends on client capabilities, and describes the fallback when a name matches no single exercise (found=false, up to five candidates with slugs, shows nothing).

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?

The description is front-loaded with the core purpose and remains reasonably concise. The three sentences are structured logically: primary action, return details, and fallback behavior. The first sentence is somewhat list-heavy but each component earns its place.

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 read-only tool with no output schema, the description adequately explains what is returned and the fallback behavior. Annotations cover safety, and the two parameters are fully described in the schema. The only minor gap is the absence of explicit sibling differentiation, but overall the definition is complete enough for an agent to call it correctly.

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 both parameters (locale and exercise) are fully documented in the schema. The description reinforces the exercise parameter's accepted forms (slug, id, or name) and explains the fallback for ambiguous matches, but it adds no new semantics for the locale parameter. Baseline 3 is appropriate when the schema already carries the parameter documentation.

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?

The description uses a specific verb and resource: 'Shows the user one exercise from AIm's catalog' and enumerates the content returned (picture/animation, technique, summary, cues, safety, progressions). It is clear what the tool does, but it does not explicitly differentiate itself from siblings like list_exercises or search_exercise_pool.

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 'Shows the user one exercise' and the fallback behavior for ambiguous names, but there is no explicit guidance on when to use this tool versus list_exercises or search_exercise_pool. The description lacks exclusion or alternative-selection criteria.

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