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

Beyond the readOnlyHint and idempotentHint annotations, the description discloses important behavior: text-like files are returned as text, non-text as base64, and large files are truncated with a notice in the response. This gives the agent a concrete model of what to expect.

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 short, information-dense sentences with zero filler. The main purpose is front-loaded, and the encoding/truncation details are concise and directly actionable.

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 read-only tool with two well-documented parameters, the description covers the return format, encoding, and truncation behavior. The schema handles parameter provenance and defaults, and annotations cover safety. Nothing critical is missing for an agent to invoke it 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%: the attachment parameter is documented as coming from list_issue_attachments or get_issue, and maxBytes has a clear default and purpose. The description adds no additional parameter-level meaning, 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 opens with a specific verb ('Return the contents') and a clear resource ('a file attached to an issue, a comment, a doc or a project'). It clearly differentiates from siblings like attach_file (write) and list_attachments (list) by focusing on reading content.

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 makes it clear this is the tool to use when you need the contents of an existing attachment, but it does not explicitly mention alternatives or exclusions. An agent can infer the context from the wording, but no direct when-not-to-use guidance is given.

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