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

Annotations already disclose the key profile: a non-read-only, non-destructive, idempotent write. The description adds little beyond that, and what it does add ('in their words', 'carbs if given') restates the parameter schema rather than revealing new behavior. It says nothing about whether an entry is created immediately, whether duplicate logs are possible despite idempotentHint, or what is returned.

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 the action and resource front-loaded, and both parentheticals carry real information (a concrete example and the conditional carbs rule). Nothing is wasted or padded.

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 three-parameter write tool with full schema coverage and clear annotations, the description covers what to log and how to phrase it. The main residual gap is that no output schema exists and the description never says what happens on success (e.g., a confirmation or created entry), though that is a minor omission for a simple logging tool.

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%, including the time format variants, the omit-for-now default, the never-in-the-future rule, and the conditional carbs semantics, so the schema carries the load and the baseline of 3 applies. The description's 'with carbs if given' merely echoes the schema's 'only if the user says so' rather than adding new meaning.

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 (log) and resource (something eaten or drank), with an example and an optional scope ('with carbs if given'). The food/drink resource cleanly separates it from siblings like log_exercise, log_glucose, and log_insulin without needing to name them.

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: capture food/drink in the user's own words, and include carbs only when the user volunteers them. There is no explicit when-not guidance, no mention of how this relates to siblings such as log_glucose or delete_entry, and no note about correcting a mistaken entry.

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