read_exercise

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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. Beyond that the description adds real context: built-in exercises return English instructions, custom ones return a media hash usable by other tools, weightMeans semantics for dumbbell/kettlebell, and that lastWeight is expressed in the profile unit. It does not say what happens when the id is unknown, which keeps it from a 5.

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?

Everything is crammed into a single run-on sentence with nested parentheses and back-to-back field lists, which is hard to parse. The volume of information is defensible given there is no output schema, but front-loading and structure are weak.

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?

With no output schema, the description carries the full return contract, and it does so thoroughly: it separates built-in versus custom field sets, lists profile note, favourite status, weightMeans and lastWeight, and cross-references the media tools. The only material omission is error behavior for a missing or malformed id.

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 100% with a single well-documented id parameter (pattern plus example and a pointer to read_exercises), so the schema carries the load. The description adds nothing about the id itself, so the baseline 3 applies.

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 opening fragment 'One exercise by id' gives a specific verb+resource and the singular form implicitly contrasts with the sibling read_exercises. However, the rest of the description devolves into an enumeration of returned fields rather than sharpening the purpose, and it never explicitly names read_exercises as the list counterpart in the description text itself (only the schema does).

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 rather than stated: fetch one exercise's full detail when you already have an id. The only routing signal is that a custom exercise's hash 'works with write_download_media and delete_media', which points to related tools but does not tell the agent when to prefer this over read_exercises or read_exercise_history.

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