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

With no annotations, the description carries the full behavioral burden and does so well: it discloses writes vs reads vs deletes, per-action ACL checks (kvp_put, kvp_get, kvp_delete, kvp_list), metering (1 kvp_ops), and return shapes for each action. It stops short of error behavior, atomicity, or rate limits, but is unusually thorough for an unannotated tool.

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?

The description front-loads purpose, then routing guidance, then per-action details. Every sentence has a job, and the density is appropriate for a four-action tool. It could be slightly more scannable with list formatting, but there is little wasted text.

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, so the description compensates by listing return payloads for each action ({value, budget, keyBudget}, {ok, budget, keyBudget}, {keys, cursor, budget, keyBudget}). Combined with full schema coverage for parameters and explicit sibling alternatives, it is nearly complete, missing only error and edge-case behavior.

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 the baseline is 3. The description largely restates action-specific requirements already documented in the schema (key required for put/get/delete, namespace allow-list, action behavior) and adds no new parameter syntax, format, or constraint details beyond what the schema provides.

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 and write arbitrary namespace strings') and enumerates the four supported actions. It clearly distinguishes this tool from siblings manage_memory, index_document, search_documents, and get_storage_summary, so an agent can route without opening schemas.

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 directs to manage_memory when the namespace is prefs, facts, or run, to index_document/search_documents for semantic search, and to get_storage_summary for inventory. It also states a clear exclusion ('No email'), leaving no ambiguity about when to use this tool versus alternatives.

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