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

With no annotations, the description carries the full behavioral burden. It discloses that the operation is append-only, that the source of truth is evidence.attached on run:{id}, and that a second attach to the same slot supersedes the previous pointer. It does not mention auth or error cases, but the core behavioral contract is transparent.

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 efficient sentences: the first states the action and core mechanism, the second explains the source-of-truth, supersession, and preference guidance. Every clause adds value, and the purpose 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 9-parameter tool with an output schema, the description covers the essential usage context, alternatives, and behavioral nuances. It does not mention potential errors or validation, but the output schema likely handles that. The description is sufficiently complete for an agent to invoke the tool correctly.

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 the schema already documents every parameter. The description adds context around slot/pointer supersession but does not elaborate on individual parameter formats beyond what the schema provides. Baseline 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 a specific verb (attach) and resource (evidence to a Process run) and explains the append-only mechanism. It also distinguishes from alternatives like file_create auto-attach and direct case-file mutation, making the tool's purpose unambiguous.

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 provides explicit guidance: agents should prefer this tool (or file_create with work_id) over mutating a case-file row, and it explains the supersession behavior for same-slot attaches. This tells the agent exactly when to use it and what to avoid, leaving no ambiguity about alternatives.

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