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

The description adds useful behavior beyond the annotations (storage location, overwrite semantics, the warning that old text is lost unless merged). However, the input schema and description both state the value 'replaces the old text' — a destructive overwrite of existing data — while destructiveHint is declared false. That mismatch can mislead an agent about the reversibility/risk of the call.

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?

Purpose is front-loaded and every clause carries weight (content scope, storage target, merge prerequisite, authoring constraint). The opening sentence is long and list-heavy, which slightly dilutes readability, but there is no filler.

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?

Given one parameter, full schema coverage, an output schema, and annotations, the description covers purpose, storage, prerequisites, and tone. The only meaningful gap is the unresolved conflict between the 'replaces the old text' semantics and destructiveHint=false, which leaves the agent's risk model ambiguous.

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?

With a single parameter at 100% schema coverage, the baseline is 3, and the description earns above that by explaining what the string should contain (visa sponsorship, relocation, notice period, salary, languages, self-identification, etc.) and how to populate it (merge from get_my_profile, use the user's own words). This adds real meaning over the schema's terse 'full More about you text'.

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 names a specific verb (save) and resource (standing facts about the user / the 'More about you' settings text) and explains the downstream effect (used by Apply with AI on every future application). It enumerates concrete content categories, making the tool's remit unmistakable. It only lightly differentiates from siblings, naming get_my_profile as the read counterpart rather than explicitly contrasting with update_my_profile.

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?

It gives an explicit prerequisite workflow: 'read get_my_profile first and merge with what is there, so nothing is lost,' which tells the agent when and how to prepare for this call. It also constrains authoring ('write it in the user's words; never invent facts'). No explicit when-not or alternative-tool routing is provided, but the context is clear.

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