Read the PCP metrics guide

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

readOnlyHint=true is already declared, and the description is consistent with it ('Returns the guide'). It adds useful framing that this is reference/documentation content rather than live telemetry, but says nothing about size, latency, or whether the guide is static versus host-dependent (it does take a host param). With annotations covering safety, this is adequate but not 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?

Two sentences, zero filler, and the core purpose is front-loaded before the usage instruction. 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?

An output schema exists, so return-value details are unnecessary, and the description correctly frames what the tool yields. It is nearly complete for a simple one-param reference tool; only the relationship to pcp_list_metrics is left unaddressed.

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% and the single 'host' parameter is fully documented in the schema, including localhost vs remote-SSH semantics. The description adds no parameter-level meaning, so the baseline of 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?

Specific verb+resource: 'Returns the PCP metrics guide', further qualified as a catalog of metric names and how to read values returned by the other PCP tools. This clearly distinguishes it from siblings like pcp_list_metrics and pcp_query_metrics, which return data rather than documentation.

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?

Explicitly states when to use it ('Read it before investigating performance with PCP') and a behavioral rule ('take metric names from it rather than from memory'). It does not, however, address when to prefer pcp_list_metrics over the guide, which is the closest sibling and an obvious ambiguity.

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