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

Annotations flag destructiveHint=true, and the description justifies it by explaining that keywords REPLACES the whole list by default and how to avoid that with mode add/remove. It also discloses the partial-update semantics ('Only the fields you pass change'). It stops short of auth/permission or reversibility notes, but adds real context beyond the annotations.

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 with purpose, then dense but relevant detail on replacement vs merge and keyword matching. Four sentences, each carrying information (destructive default, mode alternatives, regex syntax, list-first tip). 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 destructive mutation with an output schema already present, the description covers partial-update behavior, the destructive default, merge modes, and matching rules. Nothing critical to correct invocation is missing, though permission requirements are unaddressed.

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 low (25%), so the description must carry the load, and it does: it explains keywords semantics (full replacement vs add/remove merge), substring vs slash-delimited regex matching, and mode behavior. clusterId and name constraints are left to the schema, but the high-value keyword semantics are well covered.

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?

States a specific verb ('Edits') and resource ('an existing topic cluster') plus the fields it operates on (name, keyword list). 'Existing' implicitly distinguishes it from create_topic_cluster and delete_topic_cluster among its siblings.

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?

Gives clear mode-selection guidance ('mode "add" or "remove" ... which is what you usually want when extending a cluster') and a prerequisite ('Read the current list with list_topic_clusters first when replacing'). It doesn't state when to reach for a different tool entirely, but the routing within the tool is explicit.

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