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

Annotations declare readOnlyHint=false, destructiveHint=false, idempotentHint=false, openWorldHint=false. The description goes beyond them by disclosing v1 limits (text/* only, max 100 KB), stating it returns a server-computed sha256, and explaining the values are meant to be passed verbatim to submit_evidence. It doesn't explicitly warn about non-idempotency (re-uploading creates new copies), which is the one behavioral gap.

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?

Front-loaded with a bold 'When to use' line, followed by a clear paragraph covering purpose, return values, and limits. Slightly redundant in restating the storage_url+hash contract twice, but every sentence is informative.

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 2-param write tool with no output schema, the description fully covers purpose, when to use vs. alternatives, return contract (storage_url + hash), and v1 constraints (text-only, 100 KB). An agent has everything needed to invoke correctly and chain into submit_evidence.

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 content (UTF-8, up to 100 KB) and content_type (must start with 'text/'). The description reinforces the text-only and 100 KB constraints but adds no format details beyond the schema. 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?

States a specific verb (upload) and resource (UTF-8 text artifact) with concrete examples (translation, code, summary). It clearly distinguishes itself from submit_evidence by describing itself as the upstream step that produces the storage_url and hash that submit_evidence consumes.

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?

Explicit when-to-use: 'when you have no fetchable URL of your own' and 'when you don't have your own storage credentials (gist, S3, etc.)'. It names the consumer tool (submit_evidence) and the agent types that need it, leaving little ambiguity about when to pick this over storing externally.

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