context_status

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

With no annotations provided, the description must carry behavioral disclosure. It does mention the tool is cheap to call contaminating performance traits)Skip it also lists what it reports (fullness, pinned items, compaction advice). However, it does not explicitly state that it is a read-only operation with no side effects, nor does it mention any error conditions or output format. For a read-only status tool, the read-only nature is implied but not stated, and that is an omission given the description carries the full burden without annotations.

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, no filler. The first sentence states exactly what the tool reports (fullness, pinned items, compaction advice) and the second provides the usage context. Front-loaded and every word 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?

The description clearly covers what the tool reportsheb, when to use it, and that it is cheap. Since no output schema is defined, the description compensates by listing the key diagnostic outputs. The only minor gap is precisely how the response is structured (e.g., numeric vs. textual), but for a status/decision support tool, this is sufficient.

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 single parameter session_id is fully described in the schema (100% coverage) with a clear explanation about reusing the same ID for memory accumulation. The tool description itself does not add specific details about the parameter beyond what the schema already provides, so a baseline of 3 is appropriate.

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 reports session fullness, pinned items, and compaction advisability. It names a specific verb ('report') and resource (session status), and distinguishes it from siblings like context_compact and context_append by focusing on status inspection rather than mutation.

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 tells the agent when to call it ('use it to decide whether you need to compact before adding more') and characterizes the call as cheap, signaling it's a low-cost diagnostic step. This is clear guidance with a specific decision context, making alternatives obvious.

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