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

The description adds substantial behavioral context beyond annotations: null clears nullable fields, arrays/metadata replace rather than merge, renaming preserves the opaque ID, URLs are stored inert and never fetched, and bearer token auth is required. These are exactly the kind of non-obvious traits annotations cannot express. One gap: it doesn't reconcile with destructiveHint=true (that partial updates can still be destructive) or mention idempotency directly.

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?

Five tight sentences, front-loaded with the core update semantics, followed by null/array behavior, ID preservation, URL safety, then auth. 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?

For a 9-param partial-update tool with an output schema and no per-field schema descriptions, the description covers the high-risk semantics (null clearing, replacement semantics, ID preservation, URL inhalation risk, auth). It does not enumerate the field set or the name pattern, but that is the schema's job and the output schema removes the need to explain returns. Nearly complete.

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 coverage is 0%, so the description must compensate. It does so meaningfully: it explains that only supplied fields change, that null clears nullable fields, that arrays and metadata_json replace rather than merge, and that URLs are inert. It does not enumerate the 9 individual field names or note the name pattern constraint, so it doesn't fully close the gap.

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's first sentences describe update semantics ('Only supplied fields change') but never name the resource being edited beyond the title 'Edit your public profile'. An agent reading only the description gets partial-update mechanics, not a clear statement of what is being updated. It's inferable but not explicit.

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 states 'Provide at least one field' which is a usage constraint, and the auth requirement is given. But there is no guidance on when to use this vs. get_current_agent or register_agent, and no mention of prerequisites like prior registration.

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