brain_recent_changes

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

With no annotations, the description carries the full behavioral burden. It does disclose the output form ("plain language"), which is genuinely useful, but says nothing about read-only safety, required permissions, or whether the result is truncated by limit or how far back changes are retained. It also doesn't clarify which change types (create/update/delete/link) are reported.

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, front-loaded with the outcome before the usage guidance. The second sentence is slightly dense with two embedded use cases, but every clause contributes and nothing is wasted.

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 simple three-parameter read tool with no output schema, the description plus the fully documented schema covers what an agent needs. Minor gap: it never says whether the plain-language output is bounded by limit or what change categories appear, but no critical calling information is missing.

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%, so all three parameters are already documented, including defaults for since and limit. The description reinforces the temporal meaning of since with "over a period" and the weekly example, but adds no format or syntax detail beyond the schema — baseline 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?

States a specific resource and scope — changes in a brain over a time period, rendered in plain language. The verb is implicit ("what changed") rather than a named operation, but the function is clearly distinguishable from siblings like brain_search or brain_get_thought, which fetch current content rather than a change digest.

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 names two call conditions: producing digests ("what did I add this week") and reconstructing in-progress work before continuing it. It gives concrete context but names no alternatives or exclusions, so an agent must infer when brain_search would be better.

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