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

Annotations already declare readOnlyHint, idempotent, non-destructive and closed-world, so safety is covered. The description adds genuinely non-obvious behavioral context: it returns readiness state, and a successful upload does not by itself mean the media is ready. It omits return shape and whether results are paginated, but the readiness caveat is real added value.

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 compact sentences with the core action front-loaded and no filler. The second sentence is terse to the point of being slightly cryptic, but it carries important warning content rather than waste.

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 read-only list tool with fully documented params, this is close to sufficient. However, with no output schema, the description introduces the concept of 'readiness' without saying what readiness fields or states come back, which is the main thing an agent would need to interpret the response.

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% and both parameters carry their own 'never a personal platformId' documentation, so the schema does the heavy lifting. The description's 'Company media IDs only' cautions about ID provenance but does not map clearly onto the two declared parameters (workspaceId, postGroupId), leaving a small mismatch. 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 a specific verb and resource: read saved media and readiness for a single post. It is distinguishable from siblings like company_get_post or company_list_posts, though the shift from the name's 'company' to the description's 'Agency post' introduces mild terminology ambiguity about which entity scope applies.

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 second sentence gives a usage constraint ('Use Company media IDs only; a successful upload alone does not prove completion') but never names an alternative tool or states when to use this versus company_get_post or attach_media. Usage is implied rather than routed.

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