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

Beyond the annotations, the description discloses several important behaviors: deterministic output, no AI generation, rejection of unknown item ids, and a 409 on stale source_stage. These add real context beyond readOnly/destructive/idempotent hints and align with the annotations' write-oriented profile.

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?

A single dense sentence with zero filler. The primary action and key constraints are front-loaded, followed by preconditions and failure semantics. Every clause adds information needed to call the tool correctly.

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 tool with nested objects, no output schema, and safety hints, the description covers the essential call conditions: keying, level range, deterministic behavior, competency requirement, unknown-id rejection, and stale-version conflict. It doesn't describe the response/return shape, but with no output schema that is less critical; minor gap only.

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 semantic load. It explains that anchors are keyed by item id with levels 1-4 and that source_stage has a stage/version shape causing 409 on staleness. This meaningfully compensates for the schema's bare structure, though it doesn't enumerate every nested constraint.

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?

Description states a specific verb ('Upsert'), a precise resource ('behavioral anchors for draft items'), and key identifiers ('keyed by item id with levels 1-4'). The explicit 'deterministic, no AI generation' contrast cleanly distinguishes this from sibling generate_anchors.

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?

Provides useful usage context: requires competencies, rejects unknown item ids, and has a stale-version failure mode. However, it never names an alternative tool like generate_anchors or delete_anchors explicitly; the 'no AI generation' note implies the distinction without an explicit when-to-use/when-not-to-use rule.

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