add_source

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

Adds genuinely useful behavior beyond annotations: a risk gate refuses sensitive content (keys, tokens, private keys, personal data on unofficial backend) before data leaves the machine. This tells the agent about a failure mode it would otherwise not know. It does not address what happens on refusal (error type, partial writes) or confirm the idempotentHint behavior, so not a 5.

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 core action and examples, followed by the safety constraint. The parenthetical multi-clause safety sentence is slightly dense but each part earns its place by naming distinct refused categories.

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?

An output schema exists, so return values needn't be described, and the safety gate is a welcome addition. However, for a two-required-parameter write tool with no schema descriptions, an agent still lacks guidance on what to supply for title/text and what a gate refusal looks like in practice.

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 coverage is 0% – neither title nor text has a description in the schema. The description's phrase "text source" loosely implies text is the content, but title semantics and formatting expectations are left entirely undocumented, so it only partially compensates for the coverage gap.

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 verb and resource ("Add a text source ... to the brain") and gives concrete examples of what counts as a source (project note, ADR, runbook). It doesn't explicitly differentiate itself from siblings like list_sources or ask, but the add-vs-read distinction is evident.

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 examples imply the kind of content this tool is for, but there is no explicit statement of when to use this versus ask or list_sources, nor any prerequisites. Usage must be inferred from the examples alone.

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