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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world, so the safety profile is covered. The description nonetheless adds meaningful behavioral context beyond that: runtime readiness is not probed by this read, and connected-account targets are surfaced as opaque workspace-scoped targetKeys — both non-obvious facts about what the call returns and verifies.

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 sentences, each front-loaded with the operation first and the negative scoping last. Dense and jargon-heavy ('runtime readiness', 'targetKeys'), but no sentence is filler given the read-only contract it is establishing.

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 an output schema present, return-value structure need not be documented, and annotations cover the safety profile; the description supplies the remaining semantic framing (lifecycle state, capability vs. readiness, opaque targets). Only the absence of explicit routing to the preview sibling keeps it short of fully complete.

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 0%, so the description must carry the burden for postId, and it only adds the qualifier 'workspace-verified' — implying the post must belong to the caller's workspace. It does not explain scoping, error behavior for foreign posts, or why a UUID is required, leaving meaningful gaps for a zero-coverage schema.

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?

The first sentence gives a specific verb and resource: it reads a workspace-verified Post's image/video request, lifecycle state, and media capabilities. That is clearly distinct from siblings like preview_post_media_request_change, but the alternative is only gestured at via 'This does not start or change media work' rather than named.

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?

The description states what the tool does not do (start or change media work), which implies a read-only usage context, but it never explicitly says when to call this versus preview_post_media_request_change or get_source_image. The usage boundary is inferred rather than stated.

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