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

Annotations already declare readOnlyHint=false and destructiveHint=true, so the safety profile is covered structurally. The description adds a genuine behavioral trait the annotations cannot express: partial-update semantics ('Send only the fields that should change'), which tells the agent omitted fields are preserved rather than cleared. It does not address permissions, error behavior, or how this squares with the destructive hint, so it is not a 5.

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?

Front-loaded one-line statement of what the tool does, followed by a tight trigger list, then the two operational rules. No filler, no restatement of the title, and the required-parameter note is brief enough not to be waste.

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 annotations carry the safety profile; what remains for the description is usage routing and edit semantics, both of which are present. It lacks any note on what happens if team_uuid is invalid or an icon value is rejected, a minor gap for a simple 3-parameter update.

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 100%, so the three parameters are already documented and the baseline is 3. The description adds meaning the schema cannot convey: that name and icon are individually optional and only supplied fields are modified, plus reinforcement that team_uuid is mandatory. This is a modest but real value-add over the schema.

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 ('Update') and resource ('an existing team') and scopes exactly which fields are affected (name and/or icon), which is more precise than the title 'Update account team'. It does not explicitly contrast itself with neighbors like create-account-team or delete-account-team, but the operation is unambiguous without a schema lookup.

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 two concrete trigger conditions ('user asks to rename a team', 'user asks to change a team's icon'), which is real when-to-use guidance. It stops short of any exclusion or alternative-tool routing, so an agent gets no explicit 'do not use this for X' signal.

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