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

Annotations already cover safety (readOnly, non-destructive, closed-world), and the description adds genuinely useful behavior: newest-first ordering, a hard cap of 10 results in search mode, and that search overrides the other filters. It does not describe pagination totals or result shape, but the key behavioral quirks are disclosed.

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?

Compact and front-loaded, with the core action and ordering stated first and the search caveat second. The dense semicolon-chained phrasing is slightly harder to scan than a short bulleted form, but nothing 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?

For a read-only listing tool with no output schema, the description covers ordering, default type, filter/search interplay and the search result cap. Return-value shape and total-count behavior are left implicit, which is acceptable given the absence of an output schema but leaves a small gap.

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 67% and the description fills gaps: it clarifies the type values including that a MIME type such as image/webp maps to its kind, and states the precedence relationship between search and the other parameters. limit/offset remain undocumented beyond the schema, so not a full 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 and resource ('List the media assets in a project's library') plus an ordering guarantee ('newest first') and default scope (images by default). An agent can distinguish this from search_stock_images and list_entries without opening the 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?

Clearly explains the branch between filter-mode and search-mode, including that limit, offset and tags are ignored during a search. It does not name sibling alternatives (e.g. search_stock_images for non-project imagery), so it stops short of full alternative routing.

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