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

Goes well beyond the annotations (readOnlyHint=false, destructiveHint=true, idempotentHint=true), disclosing the 10-second propagation window, that in-progress runs and running Streamlit apps keep the old value, that the old value is not retained, the owner/admin permission requirement, the 'Secret not found' error, and plaintext exposure in the client transcript. Nothing contradicts the annotations; 'old value is not kept' aligns with destructiveHint=true.

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?

It is dense and long, but front-loaded with the core action and critically informative throughout; nearly every clause (propagation timing, permission, error, return shape) earns its place. Minor verbosity keeps it just shy of the top.

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?

With no output schema, the description fully specifies the return value (message plus secret _id/name/type/updated, never the value). Combined with permission, timing, and error behavior, an agent has everything needed to call it correctly.

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%, so baseline is 3, but the description adds real meaning beyond the schema: it warns the value passes through the model and is stored in plaintext in the session transcript, and clarifies secretId origin from fastero_list_secrets. This is meaningful added context over the schema's 'Write-only' note.

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 ('Replace the value of one existing text Secret') and scopes it precisely ('chosen by id from fastero_list_secrets', file Secrets unchanged). It also explicitly distinguishes from the sibling fastero_create_secret, so an agent can differentiate without opening the 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?

Explicitly says this is 'the only way to replace a value' and explains that fastero_create_secret refuses an existing name, which is exactly the when/why versus alternative guidance. It also notes file Secrets are left unchanged, scoping applicability further.

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