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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuine value by disclosing the match-quality taxonomy (exact, equivalent, alternative, closest, none), which tells the agent results may be approximate rather than guaranteed. No rate-limit or auth notes, but none needed for a local read.

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?

A single sentence with zero waste, front-loading the action and resource before the return-value detail. Nothing could be removed without losing information.

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 simple two-parameter read with full schema coverage and clear annotations and no output schema, the description covers purpose and the meaning of the result values. Only a note on how to interpret 'none' or 'closest' outcomes is missing.

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 are fully documented in the schema, including the enum for lang. The description's '0025' example duplicates the schema's own example and it never mentions the lang parameter. Baseline 3 is correct when the schema carries the burden.

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 the v2 exercise') and resource (old v1 id) plus the return shape (match quality tiers). It is clearly distinguishable from siblings like get_exercise or find_exercise_alternatives, which operate on v2 ids rather than mapping legacy ones.

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 phrase 'for an old v1 id' establishes the triggering context clearly: this is the tool for legacy-id lookups. It does not name exclusions or point to an alternative for v2-native ids, so it stops short of a 5.

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