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

Annotations already carry readOnly/idempotent/non-destructive signals, so the bar is lower. The description adds useful behavioral context: it returns a singular conversation with enumerated fields and optionally embeds threads. No contradictions with 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?

Two sentences with the core subject and behavior front-loaded, followed by a concise purpose statement. No filler or redundant restatement of the schema.

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 3-parameter read tool with strong annotations, the description and schema together cover inputs and the main return dimensions. There is no output schema, but the description's field list gives an agent enough shape to invoke it appropriately.

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 parameters are already well documented in the input schema. The description's 'optionally embedding its threads' reinforces include_threads, but adds no new parameter-level meaning.

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?

Description uses a specific verb-resource pair ('Return one Help Scout conversation') and enumerates the payload dimensions (customer, inbox, assignee, tag, status, timing details, optional threads). It is immediately distinguishable from sibling tools like helpscout_list_conversations, which return sets.

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?

The phrase 'Answers what happened in a specific support case' gives clear retrieval context. It does not explicitly name helpscout_list_conversations as the alternative for browsing many conversations, so it stops short of the strongest possible guidance.

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