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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the agent knows this is a safe read operation. The description adds detail about the content returned but does not disclose any additional behavioral traits such as data dependencies or performance implications. It does not contradict the annotations.

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 a single, dense sentence that front-loads the core concept 'Current fitness state' and lists the key components. It is concise but somewhat run-on; it could be broken into bullet points for clarity, but it remains efficient.

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?

The description gives a clear overview of the summary content, covering the main data areas. However, it does not mention default parameter values (though the schema does) or the response format, and it lacks guidance on how to interpret the summary. Given the tool's simplicity and the schema's coverage, this is adequate but not exhaustive.

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?

The input schema already provides 100% coverage with descriptions for all three parameters (training_days, nutrition_days, include_training_grid). The tool description does not add any additional meaning or context about how these parameters influence the summary, so it adds minimal value beyond the schema.

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 clearly enumerates the specific components of the fitness summary (weight trend, waist thresholds, nutrition averages, training frequency, missing data), making it distinct from sibling tools like get_focus_summary. However, it lacks an explicit verb like 'retrieves' or 'returns', relying on the tool name.

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 description provides no guidance on when to use this tool versus alternatives such as weekly_summary or get_daily_entry. No exclusions or conditions are mentioned, leaving the agent to infer usage from the name alone.

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