ctx_summary

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

No annotations are provided, so the description carries the full burden. It describes what the tool returns (project info, key rules, etc.) but does not disclose behavioral traits such as that it is read-only, whether it has side effects, or any performance considerations. The description is adequate but could be more explicit about safety and behavior.

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 description is two sentences: first sentence states purpose and use case, second lists included content. No filler words, front-loaded with the most important information. Highly efficient.

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?

Given the tool has no parameters and an output schema is present, the description is fairly complete. It tells the agent what the summary contains and its intended use. It could mention that it is a read-only operation, but the output schema likely details the return structure. The description is sufficient for a simple tool.

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?

The tool has zero parameters, so the input schema is trivial. The description adds value by listing the contents included in the summary (project info, key rules, etc.), which is beyond what the schema provides. Baseline for no parameters is 4, and the description meets that.

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 clearly states the tool's purpose: 'Get a compact project context summary for handoff between sessions or agents.' It specifies the verb (Get) and the resource (compact project context summary), and distinguishes it from sibling tools by mentioning it aggregates multiple aspects (project info, key rules, decisions, environment, recent session).

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 gives a clear use case: 'for handoff between sessions or agents.' This implies when to use it (transition times). However, it does not explicitly state when not to use it or compare it to alternatives like ctx_get or ctx_project, which would be helpful given the many sibling tools.

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