update_alias

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

The annotations already declare readOnlyHint=false, idempotentHint=true, destructiveHint=false, and openWorldHint=true, establishing the safety profile. The description adds one genuinely useful behavioral fact not in the annotations: omitted fields are left untouched (partial update). It does not, however, warn that label_ids replaces the existing label set rather than appending, which is a meaningful mutation detail for this tool.

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 with zero filler: the first identifies the mutable fields, the second carries the partial-update rule. Both earn their place and the key constraint is not buried.

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 4-parameter mutation tool with full schema coverage, complete annotations, and no output schema, the description is adequate but thin. It omits that passing label_ids replaces the label set and says nothing about error behavior for an unknown alias_id, leaving gaps an agent would want filled before calling.

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%, so each parameter is already documented, including that label_ids 'Replace[s] the alias's labels with these'. The description only restates the field list at a high level and adds no format, validation, or null-handling semantics beyond the schema, so the baseline of 3 applies.

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 (alias) and enumerates the mutable fields: description, from name, labels. It is immediately clear what the tool mutates, but it does not distinguish itself from overlapping siblings such as set_alias_labels or bulk_set_alias_labels, which can also change an alias's labels.

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 instead of the closely related set_alias_labels, bulk_set_alias_labels, or get_alias tools. The sentence 'Only the fields you pass are changed' conveys patch semantics rather than selection guidance, so the agent must infer the correct choice from names alone.

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