context.get

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

Discloses non-obvious side effects the annotations do not cover: it writes file.changed events for new git changes and may write an auto-checkpoint, and explicitly flags "Not read-only" — valuable because the only annotation is idempotentHint=true, which alone would not warn an agent about writes. No contradiction: re-recording the same git changes is plausibly idempotent, consistent with the hint.

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 tight sentences, front-loaded with the return contract, then the write-side warning, then the routing rule. No filler and nothing buried; the side-effect warning is placed early rather than tacked on.

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?

No output schema exists, yet the description specifies the return format (Markdown) and its sections, plus the mutation behavior and the read-only fallback. For a zero-required-parameter tool this covers everything an agent needs to call it safely at session start.

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 optional `depth` parameter already enumerates summary/recent/full semantics in the schema, so the description need not repeat it. The description adds no default-behavior or formatting guidance for depth, leaving this at the baseline.

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 plus resource (returns session context as Markdown) followed by an enumerated payload: current task, progress, decisions, blockers, changed files, tests, next action. It also explicitly contrasts itself with sibling context.read, so an agent can distinguish it without opening either schema.

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?

Gives an explicit trigger ("Call it at the start of every session") and names the alternative with the exact selecting condition ("use context.read instead when the client only allows read-only tools"). Both the when and the when-not are stated, not inferred.

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