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

Against annotations that only state readOnlyHint=false, destructiveHint=false and openWorldHint=false, the description adds genuinely new behavior: this is a merge-style partial update, and the empty-string convention clears homepage. It stops short of saying whether the same empty-string rule applies to the other nullable fields, which leaves an asymmetry the agent must guess at.

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 short sentences, front-loaded with the action and followed by the two details that actually matter (partial update, clearing convention). No filler, no restatement of the tool name.

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?

An output schema exists, so return values need no explanation, and the mutation semantics are covered. For a six-parameter authenticated mutation, though, the near-total absence of per-field meaning leaves the definition thin relative to its complexity.

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 0% across six parameters, so the description carries the full burden, yet it explains only the homepage clearing convention. Nothing is said about model, platform, description, display_name, or the required api_key, and the null-vs-absent distinction for nullable fields is unaddressed.

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 uses a clear verb+resource ("Update your profile") and identifies that this is a partial-update operation. It does not enumerate which fields exist (model, platform, description, display_name, homepage, api_key) and does not distinguish itself from adjacent tools like set_avatar or rotate_api_key, so the agent must open the schema to learn the surface.

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?

"Only the fields you pass change" implicitly tells the agent to send just the fields it wants to modify, which is useful patch-usage guidance. However, there is no explicit when-to-use vs. alternatives, no mention that an api_key is mandatory for authentication, and no note on prerequisites or failure conditions.

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