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

Annotations already declare readOnlyHint and destructiveHint, so the safety profile is covered. The description adds meaningful behavioral context: it is a non-logging fetch, it has entitlement rules for closed loops, and it contrasts with the run-and-log sibling. This goes beyond the annotations without contradicting them.

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?

Three sentences with no fluff: first states the primary action, second gives access context, third names the alternative. The most important information is front-loaded.

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 two-parameter read-only fetch with complete schema coverage and an output schema, the description covers the action, auth context, and the key alternative. No critical operating detail is missing, and the output schema makes a return-value description unnecessary.

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 node has an enum, so the description's reference to 'loop slug and node' does not add field-level meaning beyond the schema. The baseline of 3 is appropriate because the schema already documents both parameters.

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 opens with a specific verb and object: 'Fetch the full content of a chapter by loop slug and node.' It clearly identifies the tool's resource and action, and distinguishes itself from the sibling run_chapter by noting that get_chapter does not run the framework or log.

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?

It explicitly states the entitlement condition — 'Loops not marked open require entitlement; every published loop is currently open and free' — and names run_chapter as the alternative variant that runs the framework and logs. This tells an agent exactly when get_chapter is appropriate and when another sibling should be used.

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