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

Annotations already cover the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false). The description adds one genuinely useful behavioral detail: only the fields supplied are changed (partial update), consistent with the non-idempotent hint. It says nothing about permissions, whether changes are immediate/live, or what happens on invalid keys.

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?

Two compact sentences, front-loaded with the core action, then the id source, then the payload keys. Every clause carries information and nothing is 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 mutation tool with annotations covering safety and no output schema, the description supplies the action semantics, the id acquisition path, and the full accepted key list for a nested object. Remaining gaps are minor: no note on the required `site` parameter or error behavior on unknown keys.

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 only 33% (just 'label' and 'serviceArea' are described), so the description must compensate, and it does by enumerating all eleven accepted keys inside `profile`. It adds names but not per-key semantics, and never explains `site` or `locationId`, which keeps it below a 5.

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 states a specific verb and resource ('Changes the fields given on one saved location'), making clear this is a partial edit of an existing location rather than a create. It doesn't explicitly name add_business_location or delete_business_location as siblings, but the word 'saved' plus the id-lookup instruction differentiates it well enough.

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 a concrete prerequisite: 'Use list_business_locations for ids', which routes the agent to the right discovery tool before calling this one. It does not state exclusions (e.g. when to prefer add_business_location or how to delete), so it stops short of full when/when-not guidance.

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