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

Annotations already declare readOnly/idempotent/non-destructive, and the description goes well beyond them: it discloses a per-org concurrency limit ('a second link call issued while one is in flight comes back with `reason: busy` without running'), the pagination contract (`next_offset` loop), and the semantic ambiguity of `found: false` (absent vs. out-of-scope are indistinguishable). It also explains the authorization model: the link is what grants the body, hence no storage pointer.

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?

The one-line summary is front-loaded, followed by tightly grouped usage, behavior, Args, and Returns sections. Every sentence earns its place — the busy/concurrency note and the found:false ambiguity are actionable, not padding. Length is justified by the tool's pagination and concurrency complexity.

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 the tool's complexity (pagination, partner-org scoping, concurrency limits), the description covers everything an agent needs: when to call it, when to use the sibling instead, how to page through results, what busy means, and how to interpret found:false. The explicit Returns contract complements the output schema rather than duplicating it.

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 Args section largely repeats the schema verbatim, but the narrative adds meaning beyond it: it explains the link_id/event_id relationship ('the link surfacing that event is what grants its body') and how offset/limit participate in the pagination loop via `next_offset`. That pushes it a step above baseline, though the Args block itself adds no new parameter detail.

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?

Opens with a specific verb+resource+mode: 'Read one linked partner event's body, paged.' It then explicitly distinguishes itself from the sibling `get_memory_content` ('Do not use it for the caller's own events'), so an agent can tell them apart without inspecting schemas.

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?

States exactly when to use it ('when a partner search result's summary lacks the detail needed to answer') and when not to ('Do not use it for the caller's own events; use `get_memory_content` for that'), naming the alternative explicitly. Nothing is left to inference.

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