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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds genuinely useful behavior beyond that: empty sections signal unfilled data, and a cost estimate of ~1410 tokens for a filled profile lets the agent budget context.

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 labeled lines (Purpose/When/Cost) with zero filler, and the core purpose is front-loaded ahead of the usage condition and cost note. Every sentence carries distinct information.

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 an output schema present, the description need not explain return values, yet it still flags the one interpretive detail an agent needs (empty section = not filled in). Cost disclosure plus usage trigger makes this complete for a zero-param read 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?

The tool takes zero parameters, so the baseline is 4; there is no parameter syntax or filtering behavior the description could usefully add. The description's note about per-section emptiness is output semantics rather than parameter 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 ('Read') and resource ('the user's profile') along with the shape of the content ('section by section, with the rules for a tailored resume or cover letter'). This clearly separates it from the write-side sibling profile_update without needing to open either schema.

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 'When:' line gives two concrete triggers: before tailoring a resume/cover letter, or when the user asks what their profile holds. That is clear usage context, but it names no exclusions or alternatives (e.g., 'use profile_update to change it'), so it stops short of the explicit when/when-not pairing.

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