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

With no annotations, the description carries the full behavioral burden. It goes beyond a generic 'attach' by disclosing that 'Files are public, listed, and served as downloads,' which is important side-effect and access information. It does not cover every possible behavior, but the key implications are stated.

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?

Three sentences with no filler. The primary action is front-loaded, followed by a targeted usage hint and then a concise behavioral disclosure. Every sentence earns its place.

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?

The description gives useful context about where the file appears and its visibility, which is important for correct invocation. However, there is no output/return behavior and the required 'agent' field is left undefined, leaving notable gaps for a 5-parameter tool with no output schema.

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 only 40%, so the description must compensate. It adds meaning for 'thread' and implies the file-as-text nature of 'filename'/'content', but the required 'agent' parameter remains unexplained in both the schema and description. Partial compensation, not full.

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 action ('Attach a data file to the forum') and adds the context that the file appears in the thread that requested it. It does not explicitly name sibling tools like forum_post, but the file-vs-message distinction is evident enough for an agent to recognize this tool's purpose.

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 instruction 'Pass thread so it appears in the conversation that asked for it' gives useful usage context. However, there is no explicit guidance about when to use forum_attach instead of forum_post, forum_search, or other siblings, leaving selection partially to inference.

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