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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and closed-world, so the safety profile is covered. The description adds that rendering flows through an 'audited closed-IR render path' and produces an 'interactive MCP App', which is useful context, but it omits the behavioral constraints that actually bite: the 256KB manifest cap and the no-credential refine enforced only by gateway Zod.

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 front-loaded sentences with the core action first and the render path second. Slight redundancy in repeating the 'closed ... IR' / 'closed-IR render path' idea twice, but no wasted sentences.

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?

An output schema exists, so return values needn't be explained. But for a tool whose input is a 256KB-capped, credential-refined manifest validated by an authoritative Zod schema, the description says nothing about validation failure modes, the no-API-key rule, or that Zod (not this JSON-Schema) is the final gate. Adequate but thin relative to task complexity.

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 only 33% and the description adds essentially nothing beyond 'Pass a DashboardManifest', which merely restates the schema's own type. The offsetting factor is that the schema itself is extremely rich (nested const/enum/description on csd, api_base, Binding, Action, ComposeRequest), so the heavy lifting is done there, leaving this at the baseline 3.

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 ('Compose a live PCC dashboard') and identifies the render path ('closed, PCC-owned IR'), which meaningfully distinguishes it from the near-identical sibling render_pcc_dashboard. However, it never names that sibling explicitly, so the agent must infer the closed-IR-vs-other-IR contrast.

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?

No guidance on when to choose this over render_pcc_dashboard, no prerequisites, and no mention of the manifest validation gate the caller must satisfy. The agent is left to infer usage entirely from the name suffix and schema.

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