upload_issue_attachment

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

Annotations already declare a write operation that is non-destructive. The description adds useful behavioral constraints beyond annotations: a maximum file size limit and the requirement that the file reside on the server host. It does not mention permissions or overwrite semantics, but the added constraints are valuable.

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, front-loaded with the action followed by constraints. Every sentence earns its place and there is no redundancy.

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 low-complexity upload tool with complete schema coverage and annotations, the description supplies the key operational constraints. The only notable gap is a lack of routing clues versus similar upload tools, which is a minor omission given the tool's descriptive name.

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 baseline is 3. The description adds critical meaning for the filePath parameter beyond the schema: the file must be accessible on the MCP server's machine, and it is subject to a size limit. This is information an agent cannot infer from the schema alone.

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?

States a specific verb and resource ('Attach a local file to an issue'), which is clear and actionable. It does not explicitly distinguish itself from similar siblings such as upload_temp_attachment or import_issue_attachment, so it falls short of a 5.

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?

Provides a key prerequisite (the file must exist on the MCP server's machine), which implicitly constrains when the tool is applicable. However, it gives no explicit guidance on alternatives or when not to use it, leaving usage implied rather than stated.

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