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

Annotations already declare readOnly=false, destructive=false, idempotent=false, openWorld=true, and the output schema documents the return shape. The description still adds real context: the creation workflow position, that the returned identifierUrn must be handed to create_post, and that author_urn must be sourced from get_me. It does not disclose rate limits or what happens if media_urns are invalid, keeping it just below the top.

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?

Purpose is front-loaded and the sentences are tight, but the create_post linkage is stated twice ('to pass to create_post' and 'the single URN create_post takes'), which is mild redundancy that keeps it from a 5.

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?

Given an output schema and annotations covering the safety profile, the description still supplies everything an agent needs: prerequisites, exclusions, parameter provenance, and the downstream handoff. Nothing required to call it correctly 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 goes further by telling the agent where author_urn comes from (get it from get_me) and what media_urns semantically are, which compensates for the schema's confusing author_urn description ('Only messages from this author URN').

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?

Specific verb (Create) plus resource (LinkedIn multi-photo object) with the exact input (digitalmediaAsset URNs) and output (identifierUrn). It distinguishes itself from siblings by naming both the upstream (upload_media_from_url) and downstream (create_post) tools, so an agent can place it in the workflow without opening any 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?

Explicit when: 'Use after uploading two or more images with upload_media_from_url.' Explicit when-not: 'Not for one image.' It also identifies create_post as the consumer of the returned URN, covering the relevant alternatives and ordering.

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