plan_summary

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

With no annotations, the description carries the burden and does add real operational context: the input must be JSON from `terraform show -json`, the path is resolved relative to the server's --dir, and oversized files (256 MB default, configurable via --max-mb) are refused with a clear error. It does not state that the tool is read-only or non-destructive, which is implied only by "Overview".

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 purpose and content list are front-loaded, and the imperative "Call this first" is well placed immediately after. The long comma-separated enumeration of returned fields is dense but reflects genuine scope; the separate path paragraph cleanly isolates the input constraint.

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 the return shape need not be explained, yet the description still summarizes what the agent will get, and it covers the one input's provenance and failure mode. For a single-parameter read tool this is nearly complete; only the read-only guarantee and behavior on malformed plan JSON are unstated.

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 0% for the single parameter, so the description must compensate, and it does: it specifies the exact expected artifact (`terraform show -json tfplan`), the path resolution base (server's --dir), and the size constraint that can cause rejection. It stops short of noting path format details such as absolute vs relative handling beyond the --dir note.

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?

The description names a specific resource (a Terraform plan) and enumerates exactly what the overview contains: action counts by resource type and module, empty/destroy status, moved/imported resources, drift, output changes, failing checks, version and warnings. That enumeration distinguishes it from detail-oriented siblings such as diff_resource, explain_replace and risky_changes, which an agent can rule out once it knows this is the aggregate view.

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?

"Call this first" gives explicit ordering guidance, which is meaningful among six plan-analysis siblings. It does not name a specific alternative or state a when-not condition (e.g. use risky_changes when you only care about destructive actions), so it falls short of a 5.

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