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

With no annotations provided, the description carries the full burden. It discloses the exact return structure (fields including sessionEntries) and clarifies that sessionEntries is the raw Claude Agent SDK transcript. It also mentions authorization ('authorized to read'), which signals access control. It does not explicitly state side effects, but 'fetch' implies a read-only operation, and the level of detail is adequate.

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?

The description is two sentences with no fluff. The first sentence states the action and resource; the second provides the return-structure detail and a usage hint. Every sentence earns its place, and key information is front-loaded.

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 simple one-parameter tool with no output schema, the description is complete: it defines action, authorization, return fields, the meaning of the most complex field (sessionEntries), and the intended usage scenario. No additional details seem necessary for correct invocation.

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?

The input schema has 100% description coverage of the single parameter (investigationId is described as 'The UUID of the investigation to fetch'). The tool description adds no further semantics beyond what the schema provides, so the baseline of 3 is appropriate.

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 clearly states the tool fetches the full transcript ('brief') of a Fixter investigation, using a specific verb (fetch) and resource (investigation brief/transcript). It distinguishes itself from siblings like list_investigations (which lists) and start_investigation (which creates) by emphasizing the 'full transcript' and the return fields.

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 description provides a clear usage context: 'Use to recall context about an investigation that the engineer is currently working on via the Fixter plugin.' It does not explicitly call out alternatives or exclusions, but the intended use case is sufficiently clear for an agent to choose this tool over others.

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