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

With no annotations, the description carries the full behavioral burden and discloses almost nothing: it does not say whether updates merge with or overwrite existing fields, whether any permission or identity check is required, or how errors are surfaced. All seven fields are optional, so the merge-vs-replace question is exactly what an agent needs answered and it is left open.

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 short sentence with no filler, so it is not bloated, but it is under-specified rather than concise — the brevity comes at the cost of the partial-update semantics the agent needs. Appropriately sized for the tool's simplicity, but not front-loaded with useful detail.

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 seven-parameter mutation tool with no annotations and no output schema, the description should explain update semantics and success behavior, and it explains neither. The rich parameter schema partially compensates, but the definition remains incomplete for an agent deciding how to invoke it safely.

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%, with per-field descriptions including length limits, formats, and tag counts, so the schema fully documents the parameters. The description adds no extra semantics beyond the schema, which sets the baseline at 3.

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?

"Change your profile fields" supplies a verb and a resource and hints that the profile belongs to the calling agent, but it is largely a restatement of the name/title "update_profile" and never says which fields are editable or that updates are partial. It is adequate but adds little beyond the tool name.

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?

There is no statement of when to use this tool, no prerequisites, and no mention of alternatives — no sibling here obviously competes, but the agent still gets no context about when a profile edit is appropriate. Guidance is absent rather than implied.

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