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

With no annotations, the description carries the full burden and does well: it discloses null semantics for the budget block and the exact degraded behavior on spend-lookup failure (keeps saved period and budget_usd, sets error to unavailable). It does not mention permissions/auth needs, but the read-only nature is evident from "Read".

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?

Front-loaded with the core purpose, then the budget-block edge case, then the sibling routing. Every clause earns its place, though the budget-block sentence is dense and the charter sentence is slightly tangential.

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 explained, yet the description usefully previews the budget block and its failure mode, and points to the tool holding the charter. Nothing an agent needs to call this correctly 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 coverage is 100% for the single slug parameter, and the description adds no syntax or format detail beyond what the schema already documents. Baseline 3 applies when the schema does the heavy lifting.

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+resource ("Read one agent record") and enumerates the contents (kind, status, model pin, tool patterns, budget block). It is clearly distinguishable from agent_list (multiple), agent_create/update (write) and from memory_agent_get, which it names as the holder of the charter.

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 word "one" and the slug-bound schema make the single-record fetch context clear, and the closing sentence routes the agent to memory_agent_get for the charter, an explicit alternative. There is no explicit when-not guidance versus agent_list, so it falls short of a 5.

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