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

Annotations only cover idempotentHint and destructiveHint, so the description carries the real weight and does: login required, OWNER/ADMIN role required, server-side fetch and rehost, synchronous moderation with the same criteria as avatars (QR codes and contact-solicitation blocked), rejected images deleted immediately, and the image_content_rejected error code. That is behavior an agent could not infer from the schema or annotations.

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?

Permissions are front-loaded in a bracket tag, then purpose, then the sibling routing, then constraints, then the failure mode. It is dense but nearly every clause is load-bearing; the moderation aside ('与头像同口径') is compressed rather than wasteful.

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 two-parameter mutation with no output schema and only partial annotations, the description supplies auth requirements, input constraints, moderation side effects, the removal semantic, and the documented error code. Nothing an agent needs in order to call it correctly or predict failure is missing.

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 100%, so the baseline is 3; the description adds real constraint semantics beyond the schema by specifying accepted formats (jpg/png/webp), a 5MB size cap, and the public-direct-link requirement. It does not add anything about organizationId beyond the schema, which keeps it from a 5.

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+resource pair ('按图片链接给组织换 logo') and explicitly names the null-value branch as logo removal with the fallback behavior (首字头像). It also distinguishes itself from the sibling upload_image_from_url by declaring that tool's returned url is the input to this one, so an agent can separate the two without reading either 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?

Gives explicit routing rules: user-supplied image links or upload_image_from_url output go here, and imageUrl=null is the removal path. It also states the negative precondition that an archived organization cannot be modified, which tells the agent when the call will fail.

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