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

With no annotations, the description carries the full burden and does well: it discloses graceful degradation, that every service is optional, that unconfigured/failing services are named in `notes`, that it never crashes, and that it surfaces a deploy-incident correlation heads-up. It omits auth/credential requirements and rate-limit behavior, but the failure-mode disclosure is unusually rich.

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?

Front-loaded with the 'COMPOSITE' label and a clean (a)/(b)/(c) enumeration that maps directly to the three data sources. Slightly dense and the closing 'Never crashes' is largely redundant with 'Degrades gracefully,' but overall every clause earns its place.

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 no output schema, the description must convey the return shape, and it does: 'correlates them into one object,' names the `notes` field, and describes the correlation heads-up. For a composite aggregator, an agent has everything needed to call it and interpret the result.

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 100%, so all three parameters are already documented in the schema (repo, owner, sentry_project with env fallback). The description adds no syntax, format, or meaning beyond that, so the 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 ('start-of-shift briefing' for the on-call person) and explicitly enumerates the three fused sources (PagerDuty, GitHub deploys, Sentry). The 'COMPOSITE' framing instantly distinguishes it from the single-service siblings like github_latest_deploy and sentry_recent_issues.

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 clearly scopes the usage context ('start-of-shift briefing for whoever is currently on call'), which tells an agent when this is appropriate. It implicitly contrasts with the per-service siblings by naming what it fuses, but never explicitly says 'use X instead when you only need one source.' Clear context, no explicit alternatives.

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