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

With no annotations, the description carries the full behavioral burden and succeeds: it lists allowed extensions, states the ~22.5MB raw-byte ceiling from the 30MiB transport body limit, warns oversize calls are rejected with an opaque 413 before the tool runs, and flags the context cost of looping over binaries.

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 dense sentences that are front-loaded with the core action before constraints and alternatives. The size/transport explanation is slightly verbose but every clause conveys actionable constraints, so little is wasted.

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?

An output schema exists so return values need no explanation, and the description covers limits, extensions, and alternatives well. The only shortfall is that mime and project_id receive no semantic treatment.

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 coverage is 0%, so the description must compensate. It adds real meaning for content_base64 (base64 encoding, size cap) and implies path semantics, but project_id and especially the mime parameter (default '') are never explained anywhere, leaving a gap.

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 ('Write a binary asset into the project from base64-encoded bytes') and immediately distinguishes its niche from siblings by declaring it 'the only way to deliver an image for \includegraphics'. An agent can tell it apart from write_file and sync_from_git without opening any schema.

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 routing rules for alternatives: text files use write_file, directories/many binaries should use sync_from_git, and oversize assets go through the web app. Both inclusion and exclusion conditions are given, leaving nothing to inference.

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