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

Annotations already declare readOnlyHint/destructiveHint=false/openWorldHint=false, so the safety bar is low. The description goes further by disclosing the two views (`effective` = resolved bounds the app actually uses, `raw` = stored profile with auto/manual flags), which is behavior no annotation conveys.

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?

Front-loaded with the resource and its fields, then the two view modes. It is dense and slightly packed into two long clauses, but every sentence carries information and nothing is redundant with the 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?

With no output schema and no parameters, the description must carry the full return-value burden — and it does, enumerating the athlete block fields, the zone targets, and the difference between effective and raw output. An agent knows what it will receive and how to use it.

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?

Zero input parameters, so the baseline is 4 and the description does not need to explain inputs. Its `effective`/`raw` discussion refers to output views rather than selectable parameters, so it adds no parameter semantics.

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+resource ("Read the athlete's profile") and enumerates the exact contents (FTP, threshold pace, HR bounds, zone model, athlete block). It also distinguishes itself from the sibling mutation tool by naming update_athlete_profile as the consumer of the raw/profile flags.

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?

Gives a clear downstream use ("right-size volume, ramps and fuelling") and routes the raw flags toward update_athlete_profile. There is no explicit when-not or alternative sibling for the same data, 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.