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

Annotations already establish readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds genuinely useful behavioral context not in structured data: links expire after an hour, and the tool spans both animation formats and pose stills. It does not describe response shape or auth/rate-limit traits, which keeps it short of a 5.

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?

Two short sentences with no filler, and the core purpose is front-loaded ahead of the expiry caveat. The phrase 'any format of an animation, or the still image of a pose' is slightly winding but not 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?

With no output schema, the description correctly signals that the return is a link and adds the crucial expiry fact. Combined with 100% schema coverage and read-only annotations, an agent has enough to invoke it; only the exact response field name is unstated, which is minor.

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 format, asset_id, and project_id are all documented in the schema with their enum values and UUID patterns. The description adds no per-parameter detail beyond what the schema already provides, so baseline 3 applies.

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 the resource precisely — a download link for animation formats or a still image — with 'get_download' as the implied verb. It distinguishes itself from siblings like get_animation (metadata) by being explicitly about a downloadable/expiring link, though it doesn't name those siblings directly.

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?

Usage is implied: call this when you need a file/link for an animation or pose still rather than animation metadata. There is no explicit when-to-use or when-not-to-use guidance, and no mention of which sibling to prefer for related needs (e.g., get_animation for details).

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