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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=false, and the description is consistent with them ('reads and changes nothing in Phorme'). It goes beyond the annotations by disclosing that the tool is purely presentational — 'displays only the title, counts, status and link it is given' — telling the agent it does no fetching or enrichment, which is the key behavioral fact here.

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 short sentences, zero filler, with the primary purpose front-loaded and the behavioral caveat last. Every clause 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 pure renderer with an output schema present, the description need not explain return values, and it correctly focuses on input expectations and the no-side-effects guarantee. The remaining gap is the four schema parameters with no description anywhere, which leaves an agent guessing at what counts/kind mean.

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 43%, with training_kind, warning_count, exercise_count and estimated_duration_minutes undocumented in the schema. The description partly compensates by naming what is rendered (title, counts, status, link), which maps onto those fields, but it adds no format or unit meaning for the undocumented ones. Baseline 3 for partial coverage.

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: 'show a compact Phorme card for a workout or program.' The phrase 'that was just previewed or saved' scopes it to post-preview/post-save results, which separates it from preview_workout_import and save_workout_to_phorme without naming them. It is clear what the tool produces, though it never names the siblings it is not.

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?

'Use this to show a compact Phorme card for a workout or program that was just previewed or saved' gives a clear triggering condition tied to the preview/save flow. It does not spell out alternatives or a when-not case, but the temporal condition is enough for an agent to place it correctly in a sequence.

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